Activated carbon cloths (ACCs) from denim fabric were developed by phosphoric acid activation in an inert atmosphere. The effect of acid concentration (5-15 wt %) and final thermal treatment temperature (600-950 degrees C) on yield, chemical characteristics (elemental composition, ash, total acidity), porosity development, morphology, and electrical properties of the resulting ACCs were examined. Noticeable changes in the thermal behavior of the precursor due to acid impregnation were detected from thermogravimetric measurements using comparative samples of raw and acid-treated denim. ACCs properties were dependent on a combined effect of the conditions employed, though the temperature exerted a major influence. The ACCs prepared with 10 wt % acid concentration at 950 degrees C showed maximum BET surface area (1055 m(2)/g) and total pore volume (0.53 cm(3)/g), and well-preserved fibers integrity. Almost all the denim-derived ACCs were electrically conductive, following ohmic behavior. Increasing the final temperature from 600 to 800 degrees C led to a substantial change in electrical conductivity. The ACCs were heated by Joule effect, attaining surface temperatures in the range 300-500 K. Electrical resistivity of the ACCs was found to depend on the extent of porosity development.